1. Field of the Invention
The present invention relates to piezoelectric sensors and, more specifically, to improvements to the surface of a quartz crystal monitor and related piezoelectric substrates.
2. Description of the Related Art
The QCM (Quartz Crystal Monitor) is an instrument in wide use for mass measurement. Early applications of these devices were focused on the measurement of thickness of a deposit in semiconductor manufacture. Initially the QCM was developed for the semiconductor industry to provide a means for real-time measurement of deposit thickness in the manufacture of semiconductor devices. Since that time, applications of QCM-based devices have broadened, particularly when it was discovered that the quartz crystal would operate in liquids as well as in air, and vacuum. More recently the range of applications has grown to include biochemical and environmental monitoring, explosives detection, intrusion detection. However, the sensitivity and specificity of sensors needs to improve to adequately address these new applications. Accordingly, there is a need in the art to improve the sensitivity and specificity of QCMs and other piezoelectric-based sensors for new applications.